Stitching mechanism for sewing machines



M1 939. L.R. "I -I'ARD ING Z.l 80,756,

sn'rbumq MECHANISM FOR SEWING rap calms I Filed'July 24, 1937 INVENTOR Leo R Harding ATTORNEY Patented, Nov. 21, 1939 PATENT OFFICE 2,180,756 s'rrrcuING M!1iA%ANISM FOR sawmc HINES Leo a. Harding, Burma, N. Y. Application M 24, 1937, Serial No. 155,484

2 Claims.

This invention relates to improvements in sewing machines and, although not limited to such use,is characterized by features which are particularly adapted to industrial machines, especially those of the kind in which the stitching mechanism includes a hook which is rotated at high speeds.

The principal object of the invention is a machine in which provision is made for cooling the rotary hook, shuttle, and needle and for preventing the accumulation of lint, dust and other foreign materials upon these and associated parts, this object contemplating the use of a fan which is available, if desired, as an attachment for standard types of machines.

The invention is illustrated in the accompanying drawing in which:

Figure 1 is a longitudinal section throu h a machine showing a stitching mechanism in which so the features of the invention are incorporated.

Figure 2 is a transverse section taken along line 2--2 of Figure 1.

, Figure 3 is a section taken along line 3-3 of Figure 2.

Figures 4 and 5 are vertical sections taken along lines 4-4 and 5-5, respectivelyfof Figure 1.

Figure 6 is a detail section taken along line 6-6 of Figure 3. a

Figure 7 is an end view of a modified form of fan.

The invention is illustrated, by way of example, in connection with an industrial machine of standard design. The said machine, as illustrated, includes a bed plate l0 (Figure 1). A shaft II is mounted under the said bedplate in suitable blocks i2 and I2a. It carries a rotary hook 13 which is formed with arms l4 (Figures 3 and 5). The latter extend radially from a hub 0 l5, set screws I50, which are carried by the said hub being available to secure the hook It to the shaft I I in the desired position of adjustment. The shaft I I also carries a gear IS, the said gear being one of a chain by which the shaft is con- 5 neoted to the driving motor. A sleeve I'I encases the shaft ll throughout the greater part of its length, one end of the said sleeve being mounted in the block l2 while the opposite end abuts the gear IS. The rotary hook I3 is formed 50 to provide a raceway l8 (Figure 3) for the annular rib IQ of the shuttle 20. The latter is held against rotary movement by a finger 2| which is carried by an arm 22 and which fits in a depression 23 formed in the shuttle. The bobbin 2 u is arranged in a holder 25 which is removably secured in the shuttle by a latch 26. The needle, needle bar and presser foot are indicated at 21, 28 and 29, respectively.

In accordance with the invention a fan 30 is employed to cool the parts of the stitching 5 mechanism. The said fan, as illustrated, includes forwardly directed blades II and is formed with a hub 32. The said hub fits over the hub Ii'of the hook I3 and is formed with slots 33 which accommodate the set screws lia. The fan 10 30 is removably secured upon the hub l5 by a resilient split ring 24. The latter fits in an annular groove 35 which is formed in the hub l5 and holdsthe body of the fan against the heads of the set screws iia, the said set screws also 15 serving to prevent relative angular movement between the hook and the fan. It is to be noted (Figure 5) that the blades ll of the fan are formed in groups which are arrangedto provide a space 36 opposite each of the heads of the set screws lia. The said spaces provide for access to the set screws and hence enable adjustment of the hook I: upon the shaft l-l without the necessity of removing or disturbing the position of the fan.

It is the practice to operate industrial machines of the character described at speeds considerably in excess of 4000 R. P. M. It will be apparent, therefore, that as the fan 20 rotates at the same speed as the hook IS a current of air will be directed toward the said hook, a portion of the said air passing around the hook and flowing along the under side of the bed plate while a portion of it is caused to flow between the hook and the shuttle. The hook and shuttle are thus cooled as are the walls of the raceway I8. It will also be apparent that during the intervals that the needle 21 is located below the bed plate l0 it will likewise be subjected to cooling effect of the current of air created by the fan, this being particularly desirable when heavy materials are being sewed. The current of air created by the fan also serves to carry away lint, dust and other foreign materials, thereby preventing their accumulation upon the parts of the stitching mechanism. Wearing of the parts is thus minimized-while at the same time soiling of the materials being worked upon is prevented.

The fan 30 may be incorporated in a machine as an original part or it may, if desired, be applied as an accessory to machines of standard design without necessitating changes in the constructionof such machines or in their manner of operation. In Figure 1 the hook l3 rotates in a counter-clockwise direction, the blades of the fan 30 being formed to direct the current of air toward the hook i3. It is understood, oi course, that the blades 01! the fan may be 01 any suitable design. m example, in the embodiment oi the invention shown in Figure 7 the angle of the'blades lid of the tan "a is reverse to that 01' the blades of the fan shown in Figure 1.

.The fan 30a, therefore. is capable of producing a current of air similarly to that produced by the fan 30 when the hook of the sewing mechanism is designed to rotate in a clockwise-direction.

I claim as my invention:

1. The combination with the stitching mechanism of a sewing machine, said mechanism in ciuding a hook and a shaft for rotating said hook, said hook having a hub. a set screw carried by said hub for securing said hook'to said shai't,

of aim for directing a current of air against said hook and associated parts of said mechanism, said fan having a hub which fits over the hub of said hook and which is formed with a slot for accommodating said set screw and means for securing said fan to said hook.

2. The combination with the stitching mechanism of a sewing machine, said mechanism including a hook and a shaft for rotating said hook, said hook having a hub which is formed with an annular groove, of a fan for directing a current oi. air against said hook and associated parts of said mechanism, said fan having a hub and a resilient ring which tits in said groove to secure the hub of said i'an upon the hub of said LEO R. HARDING.

hook. 

